05-24-2003, 03:14 PM
Hi,
If time travel is possible, we would need to establish some kind of communication with the distant future to let them know we want them to come visit us.
Why? I don't see this at all. Consider "space" travel. If I want to go to the grocery store, do I have to wait for a clerk to call me and invite me? No. I simply hop into my car and go. Why do you think that time travel would be different in this respect?
The first thing we need to know is how a single particle behaves when motionless (or without time).
We know this, quite well. Also "when motionless" and "without time" are not the same thing. Being motionless simply means that in a given inertial reference frame the position does not change over time. To consider a particles world line without time is meaningless nonsense. As opposed to, say, Jabberwocky which is meaningful nonsense.
If we consider time to be a perpetually moving entity,
If we do that, then we've generated a model that does not work right and is too limited for useful speculation. If we did that, then our premise would be wrong, and from it we could generate any form of nonsense. The problem with "a perpetually moving entity" is in the very definition of motion: the change in position over time. Thus, your consideration boils down to "if we consider time to change it's position over time". I'm not even sure how to scan that sentence.
something moving "faster" than the maximum speed allowed in the present would be propelled into the future.
Total confusion. If by "speed" you mean what is conventionally meant, then you are totally backwards. Something moving relative to you faster than the speed of light would be traveling into your past.
I've always had the understanding that a complete lack of motion was reflected by absolute zero.
Again, relative. If I'm on a spaceship doing, say, 0.5c relative to you, and I have an atom in its ground state trapped in a laser well, that atom is at absolute zero relative to me. Its internal energy, relative to you, is also zero but its total energy is not. Which is why temperature, and thus absolute zero, can hardly be defined and is relatively useless in such a discussion.
Approaching absolute zero would seem to be the slowest speed in the present relative to everything else.
What "everything else"? There is no background structure of fixed rods with which to measure. *That* is the fundamental basis of relativity. All measurements are relative to some reference frame. That is especially true of measurements of speed. The only speed that is the same in all frames is the speed of light. And that is where the weirdness begins.
Sorry for picking your post apart like this, but yours was an almost perfect example of the worthless speculation based on concepts that are totally misunderstood by the poster.
--Pete
If time travel is possible, we would need to establish some kind of communication with the distant future to let them know we want them to come visit us.
Why? I don't see this at all. Consider "space" travel. If I want to go to the grocery store, do I have to wait for a clerk to call me and invite me? No. I simply hop into my car and go. Why do you think that time travel would be different in this respect?
The first thing we need to know is how a single particle behaves when motionless (or without time).
We know this, quite well. Also "when motionless" and "without time" are not the same thing. Being motionless simply means that in a given inertial reference frame the position does not change over time. To consider a particles world line without time is meaningless nonsense. As opposed to, say, Jabberwocky which is meaningful nonsense.
If we consider time to be a perpetually moving entity,
If we do that, then we've generated a model that does not work right and is too limited for useful speculation. If we did that, then our premise would be wrong, and from it we could generate any form of nonsense. The problem with "a perpetually moving entity" is in the very definition of motion: the change in position over time. Thus, your consideration boils down to "if we consider time to change it's position over time". I'm not even sure how to scan that sentence.
something moving "faster" than the maximum speed allowed in the present would be propelled into the future.
Total confusion. If by "speed" you mean what is conventionally meant, then you are totally backwards. Something moving relative to you faster than the speed of light would be traveling into your past.
I've always had the understanding that a complete lack of motion was reflected by absolute zero.
Again, relative. If I'm on a spaceship doing, say, 0.5c relative to you, and I have an atom in its ground state trapped in a laser well, that atom is at absolute zero relative to me. Its internal energy, relative to you, is also zero but its total energy is not. Which is why temperature, and thus absolute zero, can hardly be defined and is relatively useless in such a discussion.
Approaching absolute zero would seem to be the slowest speed in the present relative to everything else.
What "everything else"? There is no background structure of fixed rods with which to measure. *That* is the fundamental basis of relativity. All measurements are relative to some reference frame. That is especially true of measurements of speed. The only speed that is the same in all frames is the speed of light. And that is where the weirdness begins.
Sorry for picking your post apart like this, but yours was an almost perfect example of the worthless speculation based on concepts that are totally misunderstood by the poster.
--Pete
How big was the aquarium in Noah's ark?